1. Field of the Invention
The invention concerns a drum coating arrangement for surface coating of small parts.
2. Description of the Related Art
Various devices for surface coating are known. The coating of small parts takes place in a device with a rotating drum which, for receiving coating material, is either dunked into a coating basin (see DE 196 13 927 and DE 102 09 908 C1) or has coating material sprayed in (see DE 34 20 859 C2).
After completion of coating, the coating drum is caused to rotate rapidly, in order by means of centrifugal force to throw off excess coating material and to evenly distribute the coating on the surface of the small parts.
The maximum fill capacity of the coating drum is limited by two criteria.
On the one hand, in the case of greater fill volumes there is the danger that the small parts become unevenly distributed within the drum, which results in an imbalance during the spin process, which can be controlled only with difficulty if at all.
On the other hand, the drum is to be so dimensioned that the height through which the small particles are dropped during coating as well as during emptying of the drum (hereafter referred to as drop height) can be kept as small as possible.
These conditions lead to a reduction in the drum diameter, and therewith, the volume of the small parts to be coated.